1. Field of the Invention
The invention relates to a robot control apparatus and, more particularly, to the improvement of the setting of offset data for coordinate conversion and the setting of an origin search range.
2. Related Background Art
For example, in an arm of the robot apparatus, when a servo is once released, the operation to find out the origin is necessary to enable the robot to be used after that. Since the operation to find out the origin must be such that the origin can be found out within a predetermined range, it is necessary to set an origin search range.
A conventional range setting apparatus to set origin search range data is constructed as follows. The origin search range data which is used check an error in the origin search operation is obtained and set into a control apparatus of the robot. The range setting apparatus is constructed by a keyboard and a CPU to execute those controls. Two data of "search start count number" and "search end count number" are inputted from the keyboard to one motor and are sent to the control apparatus of the robot by the CPU. The control apparatus of the robot receives the data of the "search start count number" and "search end count number" which were sent and stores them into an internal nonvolatile RAM.
The robot apparatus has the following inherent problems. That is, differences among the apparatuses due to manufacturing errors or the like exist. In the robot control apparatus, therefore, an apparatus for compensating an offset amount which is generated due to such differences is needed. An offset setting apparatus is provided for this purpose. The conventional offset data setting apparatus for the coordinate conversion in the robot control apparatus is constructed as follows.
First, offset data to compensate the differences among the apparatuses which occur due to the errors or the like on manufacturing of the robot is obtained by measurements. The obtained offset data is set by the offset data setting apparatus.
The offset setting apparatus is constructed by a display apparatus, a keyboard, and a CPU to control them. The offset data inputted from the keyboard is sent to the control apparatus of the robot by the CPU. The robot control apparatus receives the offset data sent from the setting apparatus and stores into an internal nonvolatile RAM. The offset data stored is stored into an RAM different from the above nonvolatile RAM at the time of an initializing process of the control apparatus of the robot and is used in a coordinate converting process.
However, according to the conventional method of setting the origin search range, the origin search range data setting apparatus is constructed by the keyboard and the display apparatus and there are drawbacks such that it is necessary to set the two data of "search start count number" and "search end count number" into one motor as origin search range data and that the number of digits of the data to be set is also large.
In the conventional offset data setting apparatus mentioned above, it is constructed by the keyboard and the display apparatus and the offset data for the coordinate conversion is stored into the RAM for the coordinate converting process at the time of the initializing process of the control apparatus of the robot, so that there are the following drawbacks.
1. When the offset data is set, the setting apparatus is certainly necessary. The set data cannot be always confirmed.
2. Since the set offset data is stored into the RAM as data for the coordinate converting process at the time of the initializing process of the control apparatus of the robots even when the set value of the offset data is changed during the operation of the robot, in order to check a change in operating position of the robot by the changed offset data without exerting an influence on the operation of the robot, it is necessary to again execute the initializing process of the control apparatus of the robot.